Sure thing! We've got 342 and we're gonna multiply it by 31. That's the same as adding 342 to itself 31 times.
Step 1: 0 + 342 = 342
Step 2: 342 + 342 = 684
Step 3: 684 + 342 = 1026
Step 4: 1026 + 342 = 1368
Step 5: 1368 + 342 = 1710
Step 6: 1710 + 342 = 2052
Step 7: 2052 + 342 = 2394
Step 8: 2394 + 342 = 2736
Step 9: 2736 + 342 = 3078
Step 10: 3078 + 342 = 3420
Step 11: 3420 + 342 = 3762
Step 12: 3762 + 342 = 4104
Step 13: 4104 + 342 = 4446
Step 14: 4446 + 342 = 4788
Step 15: 4788 + 342 = 5130
Step 16: 5130 + 342 = 5472
Step 17: 5472 + 342 = 5814
Step 18: 5814 + 342 = 6156
Step 19: 6156 + 342 = 6498
Step 20: 6498 + 342 = 6840
Step 21: 6840 + 342 = 7182
Step 22: 7182 + 342 = 7524
Step 23: 7524 + 342 = 7866
Step 24: 7866 + 342 = 8208
Step 25: 8208 + 342 = 8550
Step 26: 8550 + 342 = 8892
Step 27: 8892 + 342 = 9234
Step 28: 9234 + 342 = 9576
Step 29: 9576 + 342 = 9918
Step 30: 9918 + 342 = 10260
Step 31: 10260 + 342 = 10602

So, 342*31 = 10602